Challenges in building barcode reference libraries for marine invertebrates exemplified by the genus Prionospio (Annelida: Spionidae)

The completeness of reference libraries is often a limiting factor in the effectiveness biomonitoring using molecular tools. fact that these are built upon Sanger sequencing can create substantial bias due to poor primer fits and unoptimized lab protocols. Some taxa marine macroinvertebrates known be notoriously difficult sequence traditional, PCR-based means, only about 15% bioindicator species world-wide have publicly available sequences for any genetic marker (Aylagas et al. 2014). Barcode Life Data System (BOLD) indicates an amplification rate between 46% 85% barcode region COI most commonly used invertebrates indicate pollution North East Atlantic (Capitellidae, Cirratulidae, Dorvilleidae, Spionidae Tubificidae within Annelida, Thyasiridae Mollusca). A currently on-going integrative taxonomic study on Prionospio Malmgren, 1867 (Spionidae, Annelida) exemplifies extensive issues utilizing invertebrates. was attempted amplified five pairs: three designed universal (Folmer 1994, Geller 2013, Lobo 2013), one specialized polychaetes (Carr 2011) self-designed. In addition, two DNA polymerases were tested (TaKaRa Ex Taq HS Qiagen HotStarTaq) annealing temperatures. Only obtained from total 255 PCR reactions (2% success rate). Other markers showed better rates: 58% 16S rDNA, more than 90% rates 28S rDNA Histone H3. This illustrates importance having mind when seeking complete libraries, potential multi-marker approach surveys. As costs decrease, shallow shotgun-based (genome skimming) problematic groups such as bypass regarding unfit primers also becoming viable option.